Carpentry is one of oldest fields of technology. Over the centuries, a number of devices have been developed to mark materials for cutting or positioning. Perhaps the simplest and most versatile of these is the simple square. Indeed, with no other tools except a square, a measuring device such as a ruler or tape measure, and a marking utensil such as a pencil, almost all measuring necessary to the field of carpentry could be accomplished. But, for many applications, a considerable sacrifice of accuracy and time would result from the use of only those tools. Therefore, more specialized tools have been developed. These have ranged from adjustable squares to special square adapters for marking stair risers for cutting.
Also, devices for temporarily holding pie of materials in place while they are permanently fastened have been developed. The most common of these is the clamp.
However, while carpentry is an ancient art, the field has not remained entirely static. Modern trends have encouraged artisans to try to find ways to work more quickly and more precisely. An example of a device which has helped to advance the field is found in U.S. Pat. No. 3,086,295 issued to Raymond S. Dalpe wherein a device for scribing doors so that they may be accurately cut to fit a door opening is taught.
A device for protecting surfaces from damage while fasteners are attached is described in U.S. Pat. No. 4,282,615 issued to Dale M. Tom. The Tom device includes, as an incidental feature, a mark correctly positioned to allow the tool to be used as a measuring device, for the single purpose of indicating the correct set back length for door trim. The Tom device is used simply as a measuring device such as a ruler when it is applied to the application of door trim.
One area of modern carpentry that poses a particular problem has been the sizing and placing of door trim strips. Modern construction techniques require that trim strips be placed around practically every wood framed door to conceal the junction between the door frame itself and the support framework to which it is attached. The three pieces of trim required must all be equally set back from the door edge to be attractive to the eye. Further, the pieces of trim must meet at the top two corners of the door, where they are cut with 45 degree angle ends, with no overlap or space between the parts. Meeting these two requirements simultaneously can be quite difficult. An error of only a small fraction of an inch in the length of the headpiece or the set back of any of the trim pieces can produce very unattractive results. It is especially difficult to accurately measure for the length of the headpiece, because this must be done before any of the , pieces are in place. There are, therefore, no clear points between which a length measurement can be taken at that point of the construction.
After the trim headpiece is successfully cut to the proper length, the trim strips must be positioned properly and held in place until they are fastened permanently.
Finally, for door frames that are not furnished with pre-installed door stop strips, these must be installed. Precise positioning of the stop strip is necessary for both aesthetic and functional reasons, In the past this has involved numerous operations and considerable inaccuracy using prior art methods.
All of these processes have been accomplished by using a simple measuring device to measure for positioning, and then by marking the correct locations, and then by attempting to hold the pieces on the marks while they are fastened down.
No prior art method is presently known which can quickly and accurately provide a guidemark for measuring door trim headpiece trim length. Nor is a prior art method known which can position trim strips quickly and accurately in place. Nor is a prior art method known which can quickly and accurately position door stop strips.